News Corporation executives could be vulnerable to individual prosecution by US anti-bribery authorities under the so-called "willful blindness" clause that holds company chiefs culpable if they chose to be unaware of any specific wrongdoing by their employees.

The FBI and other law-enforcers are probing Rupert Murdoch's media empire under the Foreign Corrupt Practices Act that seeks to punish US-based companies engaging in bribery abroad. News Corp is headquartered in New York.

Under the act, the company and its executives are liable to potentially severe penalties, including up to five years in prison, if it can be shown that they consciously avoided knowing about the corrupt deeds of their employees. "It's a well established prosecutorial principle that it is no defence to close your ears and shut your eyes," said Brad Simon, a former US federal prosecutor who now defends in cases of white-collar crime.

News Corporation's FCPA woes intensified sharply over the weekend after five senior journalists at the Sun newspaper and two military officials, as well as a police officer in the UK, were arrested. The eight were brought in for questioning by detectives involved in Operation Elveden investigating improper payments to police and other public officials from within News Corp's UK branch, News International.

The perils to News Corp of an FCPA prosecution in the US against the company and its executives was underlined by the revelation that a grand jury has been convened in the case of Avon Products. The Wall Street Journal reported that US authorities are probing an internal audit report compiled in 2005 that found that Avon employees had bribed officials in China, yet the company only launched an official inquiry into possible violations three years later.

In the Avon case, the grand jury is likely to be asked to consider whether executives were culpable under the "willful blindness" provision of the FCPA.

Professor John Coffee, a specialist in white-collar crime at Columbia law school in New York, said that executives were at risk of prosecution in cases where they failed to ask relevant questions about a suspicious persistent pattern of payments. He gave the metaphorical example of a driver used by a Mexican drugs cartel to transport cocaine across the border who was aware that the vehicle contained a secret storage panel but made no attempt to find out what packages had been placed inside.

As part of its response to the billowing phone hacking scandal, News Corp has amassed the most formidable team of FCPA lawyers ever assembled. "They have appointed not just one of the best lawyers in this field, they have appointed most of the best lawyers," Coffee said.

"That's not normal defensive strategy," he added.

The team is headed by Mark Mendelsohn, who as the former head of the US department of justice's FCPA section was responsible for developing much of the case law in this area.

Rupert Murdoch's younger son, James, is in a particularly sensitive position. He is a naturalised US citizen, and chairman of News Corporation in Europe.

He has come under repeated questioning by the UK parliament over precisely how much he knew about the News of the World phone hacking scandal, from which the bribery allegations have flowed. There has been no suggestion however that he had suspicions of any irregular payments to police or other public officials.

A focal point of the US investigations is likely to be whether false financial information relating to alleged improper payments was given in News International and News Corporation accounts. That could expose the company and its executives to prosecution by the US Securities and Exchange Commission.

The department of justice, working through the FBI on both sides of the Atlantic, is also likely to be exploring how much News Corporation executives in the UK were aware of a pattern of improper behaviour and if so what, if anything, they did to stop it.